This story turned up as a 'trending item' in Australia this year (2016):

Quote:

A dangerous trend in pregnant teens lighting up is emerging, as future Aussie young mums are taking on the deadly habit in a bid to give birth to smaller babies.

A 10-year Australian study revealed pregnant teens are more concerned about giving birth to a large child than the health implications cigarettes can cause, including higher miscarriage and stillbirth risks, problems with brain development, as well as asthma and allergies.

Even though most women now understand there is “overwhelming evidence” that smoking during pregnancy is harmful to the developing child, they continue to do so, said Professor Nick Macklon of Southampton University.